Asphalt mix workable at ambient temperatures with only biodegradable solvents and method of manufacturing the same

ABSTRACT

An asphalt mix comprising a pine extract, the asphalt mix having low viscosity at ambient temperatures, and workable at ambient temperatures. The asphalt mix comprises asphalt cement, biodiesel, pine extract and an anti-stripping agent. The asphalt mix is an environmentally safe and “green” product. It comprises recycled asphalt product. The asphalt mix eliminates petroleum solvents beyond trace amounts used to denature biodiesel. The asphalt mix is used for patching at ambient temperatures. Safety precautions for heat and toxicity are not necessary for use. The asphalt mix comprises only solvents that are biodegradable. The biodegradable solvents are pine extract and biodiesel. 
     A method of manufacturing an asphalt mix comprising: heating aggregate; introducing RAP to the aggregate; dry mixing the RAP and aggregate; forming a coating of AC on all aggregate during the step of dry mixing by extending the length in time of the dry mixing step; separately blending AC, biodegradable solvents, and anti-stripping agent to produce a blend; and wet mixing the blend into the RAP and aggregate mix. The biodegradable solvents are capable of making the asphalt mix workable at ambient temperatures. The biodegradable solvents comprise pine extract and biodiesel. The length of the dry mixing is extended to at least about 35 seconds. The aggregate comprises coarse virgin aggregate and fine virgin aggregate. The RAP is about 40% of the final product. The asphalt mix is stockpiled. The asphalt mix is bagged. The method of manufacturing further comprises manipulating encrusted material on the outside of the stockpiled cold asphalt mix back into the stockpile.

BACKGROUND

The present invention relates to an asphalt mix and the method ofmanufacturing the same.

Both cold mix asphalts (CMAs) and hot mix asphalts (HMAs) are known. Theinventors have identified problems with known cold mix asphalts (CMAs)and hot mix asphalts (HMAs) as discussed below.

Traditionally, cold mix asphalts are generally used for patching and hotmix asphalts are generally used for paving.

Prior art cold mix asphalts include a petroleum solvent that makes themworkable at ambient temperatures. They require precautions for toxicitywhen worked. Most prior art cold mix asphalts use only virgin aggregate.

U.S. Pat. No. 6,139,612 to Kitagawa et al., issued Oct. 31, 2000, forAsphalt Paving Mix Formed of Recycled Asphalt Concrete for Paving atAmbient Temperatures and a Process for Making the Same includes anadditive oil which is disclosed as a hydrocarbon with petroleumhydrocarbons preferred. See col. 3, lines 10-17.

Prior art hot mix asphalts are not workable at ambient temperatures asthe term suggests. They are only workable at temperatures of about 250to 325 degrees F. They require heating. Hot mix asphalts aremanufactured hot and are shipped hot. They require precautions for heatsafety when manufactured, shipped and worked. The use of recycledasphalt in hot mix asphalts is known.

U.S. Pat. No. 6,764,542 to Lackey et al., issued Jul. 20, 2004, forBiodiesel Cutback Asphalt and Asphalt Emulsion, is owned by MarathonPetroleum (hereinafter the “Marathon Patent”). The Marathon Patentdiscloses a cutback asphalt and an asphalt emulsion comprisingbiodiesel. The Marathon Patent states, “Cutback is mixed with asufficient amount of biodiesel to reduce the viscosity of the asphalt,producing, e.g., a cold patch material which is free of added liquidpetroleum.” See Abstract.

The Marathon Patent recognizes “the polluting effect of modern roads”,col. 2, line 13. The Marathon Patent further states that “[a]ll cutbackasphalts contain solvent”, col. 1, line 65, and “When used to constructa parking lot or road, the amounts of solvent used, and discharged intothe air are enormous”, col. 2, lines 1-3.

In summary, the known asphalts including asphalts for patching areinadequate for reasons identified by the inventors discussed in detailbelow.

Therefore, the need exists for a better cold asphalt mix. The presentinvention provides a better cold asphalt mix.

BRIEF SUMMARY

None of the prior art asphalts and references mentioned above is anasphalt that is workable at ambient temperatures that, isenvironmentally safe. None of the prior art asphalts and referencesmentioned above is an asphalt workable at ambient temperatures that onlyincludes biodegradable solvents. The prior art does not disclose or showpine extract as a solvent. The prior art does not disclose an asphaltmix with biodegradable solvents capable of making the asphalt mixworkable at ambient temperatures. The prior art further does not show anasphalt mix workable at ambient temperatures with biodegradable solventscapable of making the asphalt mix workable at ambient temperaturescomprising RAP. These features are not shown where the absorption of theasphalt wet mix blend of AC, pine extract, biodiesel, and anti-strippingagent into the stone is decreased. An asphalt mix not subject toproblems of toxicity and environmental hazards which is workable atambient temperatures is not disclosed in the prior art mentioned above.The prior art mentioned further does not disclose a method ofmanufacturing an asphalt mix comprising blending AC and pine extract.The prior art mentioned does not disclose a method of manufacturing anasphalt mix comprising extending a length of dry mixing RAP andaggregate. Additionally, the prior art mentioned does not disclose amethod of manufacturing an asphalt mix comprising forming a coating ofAC on all aggregate during a step of dry mixing RAP and aggregate.

In general, in a first aspect, the invention features an asphalt mixcomprising a pine extract, the asphalt mix having low viscosity atambient temperatures, and workable at ambient temperatures.

The asphalt mix may comprise asphalt cement, biodiesel, and pineextract. The asphalt mix may further comprise an anti-stripping agent.The asphalt mix further comprises course aggregate and fine aggregate.The asphalt mix further comprises recycled asphalt product. Thecomposition of the asphalt mix eliminates petroleum solvents. Theasphalt mix is used for patching. The pine extract improves workability.The asphalt mix comprises about 1% to 7% pine extract. Preferably, theasphalt mix comprises about 1% pine extract. The asphalt mix comprisesabout 24% to 32% biodiesel. Preferably, the asphalt mix comprises about28% biodiesel. The asphalt mix comprises about 40% RAP. The asphalt mixis workable without machinery. The asphalt mix is capable of beingstockpiled. The asphalt mix is bagged and stored and sold in bags. Theasphalt mix is used at ambient temperature as contemplated.

In general, in a second aspect, the invention features an asphalt mixcomprising only solvents that are biodegradable, the asphalt mix havinglow viscosity at ambient temperatures, and workable at ambienttemperatures.

The biodegradable solvents comprise pine extract.

The biodegradable solvents comprise pine extract and biodiesel ascontemplated.

In general, in a third aspect, the invention features an asphalt mixconsisting of aggregate, RAP, AC, biodegradable solvents capable ofmaking the asphalt mix workable at ambient temperatures, andanti-stripping agent.

The biodegradable solvents comprise pine extract.

The biodegradable solvents comprise pine extract and biodiesel ascontemplated

In general, in a fourth aspect, the invention features a method ofmanufacturing an asphalt mix comprising blending AC and pine extract.

The method of manufacturing an asphalt mix comprises blending AC, pineextract and biodiesel as contemplated.

In general, in a fifth aspect, the invention features a method ofmanufacturing an asphalt mix comprising extending a length of dry mixingRAP and aggregate.

The method of manufacturing an asphalt mix contemplates a length of thedry mixing to be at least about 35 seconds. The method of manufacturingan asphalt mix contemplates using aggregate comprising coarse virginaggregate and fine virgin aggregate. In the method of manufacturing anasphalt mix the aggregate is heated before the dry mix step to be hot.The method further contemplates introducing the RAP in an amount to makeup about 40% of the final product. The method of manufacturing anasphalt mix extends the length of the dry mixing until moisture issubstantially driven off. The method of manufacturing a cold asphalt mixextends the length of the dry mixing until AC from said RAP coats allaggregate.

In general, in a sixth aspect, the invention features a method ofmanufacturing an asphalt mix comprising forming a coating of AC on allaggregate during a step of dry mixing RAP and aggregate.

The method of manufacturing an asphalt mix contemplates a length of thedry mixing to be at least about 35 seconds. The method of manufacturingan asphalt mix extends the length of the dry mixing until moisture issubstantially driven off. The method of manufacturing an asphalt mixcontemplates the aggregate comprising coarse virgin aggregate and finevirgin aggregate. The method of manufacturing an asphalt mix furthercomprises the aggregate being heated before the dry mix step to be hot.The method of manufacturing an asphalt mix contemplates introducing theRAP in an amount to make up about 40% of the final product.

In general, in a seventh aspect, the invention features a method ofmanufacturing an asphalt mix comprising: heating aggregate; introducingRAP to the aggregate; dry mixing the RAP and aggregate; forming acoating of AC on all aggregate during the step of dry mixing; separatelyblending AC, biodegradable solvents, and anti-stripping agent to producea blend; and wet mixing the blend into the RAP and aggregate mix.

The method of manufacturing an asphalt mix contemplates biodegradablesolvents that are capable of making the asphalt mix workable at ambienttemperatures. The biodegradable solvents comprise pine extract. Thebiodegradable solvents may comprise pine extract and biodiesel. Themethod of manufacturing an asphalt mix extends the length of the drymixing until moisture is substantially driven off. The method ofmanufacturing an asphalt mix contemplates a length of the dry mixingstep to be about 35 seconds. The method of manufacturing an asphalt mixcontemplates the aggregate comprising coarse virgin aggregate and finevirgin aggregate. The method of manufacturing contemplates introducingthe RAP in an amount to make up about 40% of the final product. Themethod further comprises stockpiling the asphalt mix. The method ofmanufacturing an asphalt mix further comprising bagging the asphalt mix.The encrusted material on the outside of the stockpiled asphalt mix ismanipulated back into the stockpile as contemplated.

The above advantages and features are of representative embodimentsonly. It should be understood that they are not to be consideredlimitations on the invention as defined by the claims. Additionalfeatures and advantages of the invention will become apparent in thefollowing description, from the drawing, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a is a mix formula graph showing aggregate gradation havingpercent passing/percent retained on the vertical axis and size ofparticles discriminated by a sieve on the horizontal axis.

FIG. 1 b is a table listing the values graphed in the mix formula graphshowing aggregate gradation of FIG. 1 a.

FIG. 2 a is a table of the gradation analysis worksheet and gives theaggregate information.

FIG. 2 b is a table of the gradation analysis worksheet and givesaverage bin breakdown.

FIG. 2 c is a table of the gradation analysis worksheet and gives thepercent passing through the sieve for numerous sieve sizes.

DESCRIPTION

The asphalt mix of the invention comprises a pine extract, has lowviscosity at ambient temperatures, and is workable at ambienttemperatures. The asphalt mix of the invention comprises asphalt cement,biodiesel, and pine extract. The asphalt mix comprises only solventsthat are biodegradable, has low viscosity at ambient temperatures, andis workable at ambient temperatures. The biodegradable solvents comprisepine extract and biodiesel. The invention is an asphalt mix consistingof aggregate, RAP, AC, biodegradable solvents capable of making theasphalt mix workable at ambient temperatures, and anti-stripping agent.The biodegradable solvents comprise pine extract and biodiesel.

The invention contemplates a method of manufacturing an asphalt mixcomprising blending AC, pine extract and biodiesel. The invention is amethod of manufacturing an asphalt mix comprising extending a length ofdry mixing RAP and aggregate. The length of the dry mixing time isextended until moisture is substantially driven off and AC is dispersedover all aggregate. The method of manufacturing an asphalt mixcontemplates a length of the dry mixing to be at least about 35 seconds.

The invention is a method of manufacturing an asphalt mix comprisingforming a coating of AC on all aggregate during a step of dry mixing RAPand aggregate. The method of manufacturing an asphalt mix contemplates alength of the dry mixing to be at least about 35 seconds. The method ofmanufacturing an asphalt mix extends the length of the dry mixing untilmoisture is substantially driven off.

In the preferred embodiment, the inventive method of manufacturing anasphalt mix comprises: heating aggregate; introducing RAP to theaggregate; dry mixing the RAP and aggregate; forming a coating of AC onall aggregate during the step of dry mixing; separately blending AC,biodegradable solvents, and anti-stripping agent to produce a blend; andwet mixing the blend into the RAP and aggregate mix.

The method of manufacturing an asphalt mix contemplates biodegradablesolvents that are capable of making the asphalt mix workable at ambienttemperatures. The biodegradable solvents comprise pine extract andbiodiesel. The method of manufacturing an asphalt mix contemplates alength of the dry mixing step to be at least about 35 seconds. Themethod of manufacturing an asphalt mix extends the length of the drymixing until moisture is substantially driven off.

The inventor of the present invention has identified problems with theprior art asphalts.

Cold mix asphalt is asphalt cut with a solvent and workable at ambienttemperatures. Prior art traditional cold patch includes a petroleumsolvent. The petroleum may be diesel, tulene, kerosene, or naphthalene.The solvent may make it workable at ambient temperatures. Traditionally,most cold mix asphalts are 100% virgin materials.

Prior art asphalt mixes include hot mix asphalt (HMA) which is onlyworkable at temperatures of 250 to 350 degrees F.

Traditionally, cutback asphalts have petroleum solvents in them. Suchsolvents can be harmful to the environment. No one is pleased with thetraditional cutback asphalts because of the negative environmentaleffects. The toxic petroleum leaks out and causes environmental damage.The petroleum solvent also evaporates into the atmosphere.

The Marathon Patent uses biodiesel. The Marathon Patent is for pavingnot for patching. It is a cutback asphalt. The asphalt is created andused to pave as needed. The Marathon Patent has little use since hot mixasphalt is typically used for paving. There is no real world applicationfor the product of the Marathon Patent. Hot mix asphalt is readilyavailable for paving. Further, the asphalt of the Marathon Patent isbetter when warm or heated. Tests of an asphalt made substantially inaccordance with the methods of the Marathon Patent confirm that it isfor use when warm.

A product substantially in accordance with the Marathon Patent wastested and does not work for patching. It is not workable at ambienttemperatures and requires machinery to place the material. When asphaltprepared substantially in accordance with the Marathon Patent was triedfor use in patching it did not work. The worker could not get theproduct into the application such as a hole, and the product failedmiserably for patching. Mechanical machinery would have been required toget the product into the hole.

The product of the Marathon Patent further has a problem withstockpiling the material. It can not be sold in bags because thematerial is too stiff. It sets in the bag and has a short shelf life.

The asphalt of the Marathon Patent is not a cold mix asphalt or a hotmix asphalt. It is best when the material is warmed. See col. 7, lines3-16. The Marathon Patent refers to “[S]afe use of the cutback asphaltat elevated temperatures.” It further explains:

“For some applications, a customer might want to heat the cutbackasphalt to facilitate the application, promote the removal of excessmoisture on the roadway, and/or encourage prompt “setting up” of thecutback solvent, both from cooling and some evaporation of biodieselsolvent.

Use of biodiesel based cutback asphalt, especially when appliedrelatively hot, creates a new class of building materials, with lowvolatility and low toxicity, approaching that of neat asphalt cement,but which does not require the amount of heating required for aconventional hot mix application.”

Biodiesel has a low vapor pressure and does not evaporate readily.

The inventors of this application estimate that the asphalt of theMarathon Patent has a warm temperature of 130 to 195 degrees F. forworkability and placement. This is the compaction temperature. Once theasphalt is laid on the road it can be compacted with a roller at thistemperature. The material is still warm when placed.

In contrast to the invention, the asphalt of the Marathon Patent shouldbe used at an elevated temperature and stockpiled while still warm. Itmust be used while there is still residual heat from production.

The Marathon Patent states at col. 3, lines 18-21 that a pile of thepatch material “was readily worked” after two months in storage,however, patch material made substantially in accordance with theMarathon Patent could be stockpiled for only short periods of time.After a period of time of 2½ weeks to 3 weeks, the material hardened andthe entire pile was useless, but for recycling.

At Col. 1, lines 24-26, the Marathon Patent provides the followingdefinition: “Cutback asphalts-an asphalt softened with petroleumsolvent, e.g., asphalt cement with gasoline or diesel fuel, forpatching.” The Marathon Patent states “Cutback asphalts are used forpatching and some types of new road construction or resurfacing, thoughprimarily in cooler months.” Col. 1, lines 30-32. As stated in theMarathon Patent, “Conventionally, cutback asphalt is used for patching,especially in cooler climates and/or winter months. To make the asphaltsoft enough to work with, and/or reduce or eliminate the amount ofheating needed to make the material workable, a petroleum solvent isdissolved in the asphalt. Such “cold patch” materials are frequentlymade in advance and stockpiled to provide a source of material forpatching.” Col. 1, lines 45-52.

The inventors of this application estimate that Example 1 of theMarathon Patent has a temperature of 130 to 195 degrees F. for lowviscosity and workability. Otherwise, the asphalt cement would be hard.The blend is heated and made in the tank in the production facility. Thecomponents mentioned in the Marathon Patent example 1 are only about 5%of the mix. The other 95% is stone and sand. The stone and sand are alsoblended in the production facility. The mix is then stockpiled. The mixis still hot while stockpiled. A crust forms on the stockpile and thecrust may become waste material. The mix is about 150 degrees F. insidethe crust. No further heating is done, but the mix is still warm. Themix is shoveled into a truck and trucked to the site and pushed intoholes and compacted. There is no heating at the site, but the mix isstill warm.

Basically asphalt typically has petroleum products in it. Citiestemporarily fix pot holes or use temporary “Cold patch” asphalt totemporarily (even overnight) cover up holes made by construction work togain access to utilities in the street like the sewer, gas, water lines,electric lines etc. Frequently, a metal cover is put over the hole andcold patch asphalt is used to secure the metal plate until the nextmorning when the construction work begins again. The temporary asphaltis different than permanent asphalt. In the past, the temporary asphalthad petroleum products in it. The petroleum leaks out or in the summerheat can be smelled in the air. The petroleum is an environmentalproblem and gets into rain water and run off and pollutes. The MarathonPatent uses biodiesel in the asphalt instead of petroleum products andis environmentally safe, i.e. it is a “green” product. It, however, isnot workable at ambient temperatures when made and tested.

Thus, there is a need for an asphalt mix that is workable at ambienttemperature, and is environmentally safe, with only biodegradablesolvents. There is a need for an asphalt mix that is workable at ambienttemperature, and has pine extract and biodiesel solvents. There is aneed for an asphalt mix that has biodegradable solvents that are capableof making it workable at ambient temperature. There is a need for anasphalt mix that uses RAP. There is a need for an asphalt mix that canbe stockpiled and bagged and stored and sold in bags.

There is a need for a new method of manufacturing an asphalt mixcomprising blending AC and pine extract. There is a need for a method ofmanufacturing an asphalt mix comprising extending a length of dry mixingRAP and aggregate. The method of manufacturing an asphalt mixcontemplates a length of the dry mixing to be at least about 35 seconds.The method of manufacturing an asphalt mix extends the length of the drymixing until moisture is substantially driven off. There is a need for amethod of manufacturing an asphalt mix with a dry mix step thatdecreases the absorption of the asphalt wet mix blend of AC, pineextract, biodiesel, and anti-stripping agent into the stone.

There is a need for a method of manufacturing an asphalt mix comprisingforming a coating of AC on all aggregate during a step of dry mixing RAPand aggregate. The method of manufacturing an asphalt mix extends thelength of the dry mixing until moisture is substantially driven off. Themethod of manufacturing an asphalt mix contemplates a length of the drymixing to be at least about 35 seconds.

The invention is an asphalt mix for patching holes and cracks, not forpaving a street. The asphalt of the invention is used when “cold” (i.e.,at ambient temperatures) for patching and stops a hole from gettinglarger. It stops spalling, the breakup and roll out of pavementmaterial. It repairs deficiencies in asphalt material. Patching andpaving are two different applications for asphalt. The invention is foruse at ambient temperatures. It is workable at ambient temperatureswithout machinery. It is for patching and sold in bulk and bagquantities. It can be sold in bags and does not set in the bags. It hasa good shelf life for stockpiling.

The asphalt mix of the present invention is for patching, not forpaving. The invention replaces a solvent such as a petroleum solventlike diesel, tulene, kerosene, or naphthalene, with a biodegradablesolvent. Plant biodiesel is biodegradable and is a renewable solvent.The invention includes biodiesel plus a pine tar extract additive. Pinetar extract additive is also biodegradable and renewable.

Pine extract is not a biodiesel. Biodiesel can be defined as the monoalkyl ester of a long chain fatty acid derived from renewable lipidsources. Suitable sources include animal fats and vegetable oils. Apreferred material is biodiesel made from soy bean oil. See MarathonPatent, col. 3, lines 54-57. Pine extract is made from the sap and/orbyproducts of pine trees. It is a terpene hydrocarbon solid. It isordered from the company ARRMAZ and is readily available.

The asphalt mix of the invention has low viscosity at ambienttemperatures and is workable at ambient temperatures. Viscosity is theresistance to flow. Water is less viscous than molasses.

Additionally, the invention is 40% post industrial waste. This isrecycled asphalt pavement or recycled asphalt product (RAP). It isessentially old pavement.

The invention requires biodiesel and pine extract. The biodiesel andpine tar extract are blended in a blending tank. The blend is 24% to 32%biodiesel and 1% to 7% pine extract. The pine decreases the viscosity tomake the product more workable and softens the product. Both biodieseland pine extract are biodegradable softening solvents.

An anti-stripping agent may be used. This helps the asphalt tar to stayin place on the stone.

An anti-stripping agent reduces the stripping of material from thestone. Stripping is when the asphalt cement (and biodiesel/pine extract)blend strips off the stone. It hurts the integrity of the road patch.Most municipalities and states permit no more than 10% of the materialto be uncovered after a 15 minute test of the material for stripping.The low viscosity of a cutback asphalt (which includes a petroleumsolvent to cutback viscosity) increases stripping, where the asphaltcement does not bind with the stone.

In the invention, when the viscosity is lowered by the biodiesel/pineextract blend as a solvent, stripping is also increased and ananti-stripping agent is also needed.

The product of the invention includes four elements: (1) courseaggregate, (2) fine aggregate, (3) RAP, and (4) a blend of asphaltcement, biodiesel, pine extract, and anti-stripping agent. The courseaggregate is stone which may be virgin quarried stone. The fineaggregate is sand which may be virgin quarried sand. The RAP is recycledasphalt pavement graded to course aggregate. The blend is of asphaltcement, biodiesel, pine extract, and an anti-stripping agent. Asphalt isa blend of course aggregate, fine aggregate, and tar. Asphalt cement isthe tar.

In the preferred example of the invention the amount of the fourelements were as follows: (1) course aggregate-36.5%, (2) fineaggregate-18%, (3) RAP-40%, and (4) a blend-5.5%—of asphalt cement,biodiesel, pine extract, and anti-stripping agent. These percentages areapproximate. They may vary by about 1 to 2%.

In one example of the invention the amount of the elements of the blendwere as follows: asphalt cement-67.5%, biodiesel-24%, pine extract-7%,and anti-stripping agent-1.5%. These percentages are approximate. Theymay vary by about 1 to 2%. These percentages are of the 5.5% of blend(in other words, the biodiesel is 24% of the 5.5% which is the blend).

In the preferred example of the invention the amount of the elements ofthe blend were as follows: asphalt cement-70%, biodiesel-28%, pineextract-1%, and anti-stripping agent-1%. These percentages areapproximate. They may vary by about 1 to 2%. These percentages are ofthe 5.5% of blend (in other words, the biodiesel is 28% of the 5.5%which is the blend).

The invention has no water in it and is not an emulsion.

The asphalt cement is the heavy portion of crude oil from refining. Jetfuel is the light portion of the crude oil. Viscosity is the resistanceto flow of a fluid or semi-fluid. The asphalt cement or tar is moreviscous at room temperature than when heated. Traditionally, a solventwith petroleum in it is cutback into the asphalt cement to make it lessviscous and workable and easy to place. The viscosity is reduced orcutback by the solvent. The asphalt mix of the present invention is freeof petroleum solvents and uses only biodegradable solvents.

The RAP is crushed to ⅜″ and minus. RAP is screened to remove all fineaggregate. RAP course aggregate is utilized in the manufacturing.

In the invention, the material is workable at ambient temperature. Noheating is needed to work the asphalt. The invention is an asphalt thatis soft and workable and has low viscosity at ambient temperature.

Heat is applied for mixing. A temperature of about 300 degrees F. isused for mixing to melt the AC in the RAP. This temperature drives offmoisture from the RAP. The resulting temperature is approximately 225degrees F. which distributes the AC across all aggregates. Afterintroducing the AC, biodiesel, and pine extract blend, the resultingtemperature is about 190 degrees F. An ambient temperature may beachieved before use. The product of the invention may be stockpiled andbagged and may be used at room temperature.

The resulting asphalt mix may be used at temperatures from freezing toyearly high temperatures.

The asphalt mix of the invention has a shelf life that is guaranteed for2 months when stockpiled but is more typically 3-4 months in astockpile. The bagged product has a longer life expectancy and worksstill after one year.

When asphalt is stockpiled it is left out in the open and subject to theweather and elements such as rain and cold. Thus, solvents can evaporateout more readily than when the asphalt is bagged. Stockpiled asphalt hasa shorter useful life as a result. The shelf life of stockpiled asphaltin accordance with the invention is 3 to 4 months. In contrast, baggedasphalt is sealed in the bag and is less volatile. The solvents do notreadily evaporate out. The shelf life of bagged asphalt in accordancewith the invention is one year.

Further, the invention involves a mixing procedure in order toeffectively utilize the recycled asphalt tar on the recycled product.The invention is a cold patch, for use at ambient temperatures. Itprovides the advantages of not needing to heat the material for use, orafter being laid, of not having to wait for it to cool. The machineryand precautions necessary for HMA are not needed. The asphalt mix of theinvention has no toxicity, and there is no environmental hazard.

The invention further contemplates a method of manufacturing an asphaltmix. The method of the invention has a step of dry mixing RAP, and hotvirgin aggregate. The virgin aggregate comprises coarse and fineaggregate. The method of the invention contemplates extending the lengthof time for dry mixing RAP, and hot virgin aggregate as compared toprior art methods of manufacturing asphalt. In prior art methods for hotmix asphalt, the dry mixing step is about 15 seconds. In contrast, inthe invention, the dry mix step is extended to at least about 35 secondsor greater depending on the moisture content. It may take up to aboutone and a half minutes. The more moisture, the longer the length of timefor the dry mix step. During the dry mix, moisture is driven off theaggregate and the AC in the RAP is melted and coats the aggregateforming a thin coat (or film) on the virgin aggregate. The film isformed on all the aggregate, even the aggregate in the RAP, not just onthe virgin aggregate. The heat allows RAP AC to melt and coat allaggregates, virgin and recycled, evenly.

It is the understanding of the inventors of the present invention thatthe dry mix step decreases the absorption of the asphalt wet mix blendof AC, pine extract, biodiesel, and anti-stripping agent into the stone.The film creates a seal on the stone. The blend of AC, pine extract,biodiesel, and anti-stripping agent does not soak into the virginaggregate and penetrate the stone as readily. Thus, the blend of AC,pine extract, biodiesel, and anti-stripping agent does not get insidethe microfractures in the stone as readily. The thin coat or film of ACseals the microfractures so that the AC in the AC, pine extract,biodiesel blend does not necessarily penetrate these fractures. Thisreduces the amount of blended material of AC, pine extract, biodiesel,and anti-stripping agent used and is cost effective.

The inventors of the present invention theorize that the dry mix stepdecreases the absorption of the asphalt wet mix blend of AC, pineextract, biodiesel, and anti-stripping agent into the stone by creatinga membrane that seals the stone. The membrane may be an imperviousmembrane.

An expectation of penetration of AC into stone is theorized. Theeffective AC is the AC that binds the materials. The total AC is the sumof the effective material and the AC that is used for coating thematerial. Dry mix times are extended to increase the effective ACcontent of the final product. RAP AC is utilized to coat and seal allaggregate to prevent the unnecessary absorption of AC/diluent blend whenintroduced during wet mix. During the dry mix step, the RAP AC isdistributed over all aggregates (stone, sand and recycled aggregate fromthe RAP). As understood, the reclaimed AC penetrates the microfracturesin the stone and sand, sealing them with a film or coat. The thin filmor coat creates a barrier which the AC/biodiesel/pine extract blend doesnot penetrate during the wet mix step. By sealing the stone theeffective AC in the blend rises since it is not needed to fill themicrofractures in the aggregate. This allows less AC/biodiesel/pineextract blend to be used by weight.

The method of the invention increases the effectiveness of the AC, pineextract, biodiesel, and anti-stripping agent blend by forming a film onall of the aggregate that seals the stone from absorption. The amount ofblended material of AC, pine extract, biodiesel, and anti-strippingagent used is reduced. The blend of the invention is estimated to beabout 100% effective rather than just an estimate of 70 to 80% effectivefor the prior art cold mix asphalts. The inventive method and asphaltuses RAP in an extended dry mix step that forms a sealing film on allthe aggregate.

The step of dry mixing is followed by a step of wet mixing theadditional ingredients. The RAP and aggregate mix is mixed with the AC,biodiesel and pine extract blend.

Prior art cold patch asphalts typically use all virgin material. They donot use an extended dry mix step to coat the virgin aggregate with theAC from RAP. Any dry mix step for such prior art cold patch asphalts isthe industry standard of only 15 seconds. Moisture is not substantiallydriven off in just 15 seconds. Though such prior art cold patch asphaltsare workable at ambient temperatures, this is only because of highquantities of diesel solvent to cutback the viscosity. They are notenvironmentally safe and petroleum leaks from the patch to theenvironment. They should not be used near wet lands or parks.Precautions must be used to deal with the toxicity of the petroleum.

In the invention, heat is applied for blending. In the dry mix step, theRAP starts out at ambient temperature and a temperature of about 300degrees F. is used for blending to melt the AC in the RAP. Thetemperature range may be 300-350 degrees F. This temperature is achievedfor the virgin aggregate. Virgin aggregate temperatures are nearly 60%less then similar HMA temperatures using the same amount of RAP. Thetemperature then drops to 212 to 230 degrees F., preferably 212 to 215degrees F., due to the lower temperature of the RAP. This is thetemperature before the wet mix step.

The AC tanks maintain the AC at a temperature of 300 to 350 degrees F.,preferably 300 to 325 degrees F. The pine extract, biodiesel, andanti-stripping agent are at ambient temperature. They are blended intothe AC. The resulting temperature is about 210 degrees F.

In the wet mix step, the previously blended AC, pine extract, biodiesel,and anti-stripping agent are introduced and blended into the mix of RAPand virgin aggregate. After the wet mix step, the resulting temperatureis about 190 degrees F.

The benefits of the invention include:

-   -   1. an asphalt that is environmentally safe and non-toxic in use        and afterwards; and    -   2. an asphalt that is workable at ambient temperatures without        machinery.

The method of manufacturing an asphalt mix includes the followingbenefits:

-   -   1. increased effectiveness of the AC, biodegradable solvent,        anti-stripping agent blend by preventing unnecessary absorption        into the stone; and, thus,    -   2. reducing the amount of AC, biodegradable solvent,        anti-stripping agent blend needed.

The graph of FIG. 1 a shows aggregate gradation for the asphalt mix. Thegraph depicts percent passing/percent retained on the vertical axis andsize of particles discriminated by a sieve on the horizontal axis. Thegraph is a 0.45 power chart. The horizontal axis is indicative of thesize of particles retained by a sieve. At the left of the horizontalaxis, the size of the particles is given in inches (and millimetersshown in parentheses below the value in inches). The scale goes from 1½inches to ⅛ inches. At the right of the horizontal axis, the size of theparticles is indicated by ASTM sieve designation numbers from #20 to #200. (A corresponding value in millimeters is shown in parentheses belowthe value for ASTM sieve designation numbers). The vertical axis givespercent passing/percent retained. If 100% of the aggregate is passed fora sieve for 1½ inch particles, then 0% is retained. The left verticalscale gives the percent passing value, and the right vertical scalegives the percent retained value. If 48% of the aggregate is passed fora sieve for ¼ inch particles, then 52% is retained. If 0% of theaggregate is passed for a sieve with the ASTM sieve designation numberof 200, then 100% is retained. The graph shows how much aggregatematerial is passed/retained for each particle size.

The gradation is combined for all aggregates in the mix. A worksheet ofthree tables FIGS. 2 a-2 c shows values for the individual aggregates inthe mix.

A table in FIG. 1 b gives the data graphed in the graph of FIG. 1 a. Itgives values for the percentage passing in general limits, JMF (job mixformula) range, and target value. The dotted line of the graph of FIG. 1a is the target value or actual value. In contrast, the upper and lowersolid line graphs show the upper and lower limits, respectively, for themix. For example, for ½ inch particles, the target value in the table ofFIG. 1 b is 100. The graph of the dotted line has a point at 100. Fromthe table of FIG. 1 b, the general limits are 90-100. Thus, the lowerlimit is 90 and the graph shows a point at 90 percent passing. Thus, theupper limit is 100 and the graph shows a point at 100 percent passing.For ¼ inch particles, the target value in the table of FIG. 1 b is 70.1.The graph of the dotted line has a point at 70.1. From the table of FIG.1 b, the general limits are 48-82. Thus, the lower limit is 48 and thegraph shows a point at 48 percent passing. Thus, the upper limit is 82and the graph shows a point at 82 percent passing. For ⅛ inch particles,the target value in the table of FIG. 1 b is 21.1. The graph of thedotted line has a point at about 21. From the table of FIG. 1 b, thegeneral limits are 12-28. Thus, the lower limit is 12 and the graphshows a point at 12 percent passing. Thus, the upper limit is 28 and thegraph shows a point at 28 percent passing.

FIGS. 2 a-2 c are a gradation analysis worksheet comprising threetables. FIG. 2 a is the aggregate information table. FIG. 2 b givesaverage bin breakdown. FIG. 2 c gives the percent passing through thesieve for numerous sieve sizes. The row labeled Total of FIG. 2 c givesthe values listed as the target value in the table in FIG. 1 b which aregraphed in FIG. 1 a. One purpose of the gradation analysis work sheet ofFIGS. 2 a-2 c is to obtain the values graphed in FIG. 1 a.

The gradation analysis worksheet of FIGS. 2 a-2 c is to determine theproper aggregate structure in order to put together an aggregate mix. Itquantifies the matrix of the aggregate. FIG. 2 a gives the aggregateinformation for the total aggregate blend which does not include the oilor AC. It includes aggregate from the coarse aggregate, fine aggregateand the RAP. The values in the column labeled Aggregate Blend % aremaximum amounts. The coarse aggregate employed is No. 1A stone which is¼ inch stone. The table gives the following maximum values: coarseaggregate 55%, fine aggregate 5%, and RAP 40%.

The average bin breakdown table of FIG. 2 b gives values formanufactured sand as opposed to natural sand. The row labeled PAN givesthe finest particles or dust content.

The table of FIG. 2 c shows that everything passes through the sieveswith sizes 1½ inches, 1 inch, ¼ inch, and ½ inch. The row labeled Totalindicates 100% passing for these sieve sizes. The percent passingdiffers for other sieve sizes. BIN 3 is the coarse aggregate which is55% of the total blend. The coarse aggregate is 39.6 percent of whatpasses through the ¼ inch sieve. This value is obtained in the followingmanner: Looking at FIG. 2 b, for ¼ inch stone (No. 1A stone for coarseaggregate) and the sieve size ¼ inch, there is a 72% passing value. Thefollowing calculation results in the value shown in FIG. 2 c:

72×0.55=39.6

Similarly, for the ⅛ inch sieve, for the coarse aggregate of ¼ inchstone, FIG. 2 b shows the value of 15.7 percent passing. The value inFIG. 2 c is obtained in the following manner: Looking at FIG. 2 b, for ¼inch stone (No. 1A stone for coarse aggregate) and the sieve size ⅛inch, there is a 15.7% passing value. The following calculation resultsin the value shown in FIG. 2 c:

15.7×0.55=8.6

The invention provides an asphalt mix with low viscosity at ambienttemperatures, which is workable at ambient temperatures withoutmachinery and which eliminates petroleum solvents beyond trace amountsused to denature soy biodiesel. A minute amount of diesel fuel, about1/10^(th) of 1%, may be used to denature soy biodiesel. There is noproblem with leaking petroleum, no danger to the environment, and nopetroleum toxicity. The invention is a petroleum free/“green” asphaltworkable at ambient temperatures. No petroleum cutback solvents areused. The invention only uses biodegradable solvents. Those solvents arepine extract and biodiesel.

The invention contemplates the method or process for manufacturing theasphalt mix of the invention. The method is illustrated by the followingexamples:

EXAMPLES Example 1

Formulation

The mix comprised four elements in percentages as follows: (1) coursevirgin aggregate-36.5%, (2) fine virgin aggregate-18%, (3) RAP-40%, and(4) a blend-5.5%—of asphalt cement, biodiesel, pine extract, andanti-stripping agent. The RAP was crushed to ⅜″ and minus. RAP wasscreened to remove all fine aggregate. RAP course aggregate was utilizedin the manufacturing.

The composition of the blend was as follows: asphalt cement-70% PG64-22, biodiesel-28%, pine extract-1%, and anti-stripping agent-1%.

Method of Manufacture

First, there was a dry mix step which was extended to 35 seconds. Virginaggregate started at ambient temperature and was heated to 300 degreesF. The RAP started at ambient temperature and was introduced to thevirgin aggregate. The product was mixed for 35 seconds. The time for drymixing depends on the amount of moisture and is extended until allmoisture is driven off and the AC is dispersed over all aggregates.Although 35 seconds is a starting point, the time needed is relative tothe time it takes to remove moisture and distribute the AC. This couldtake as much as about a minute and a half.

The temperature dropped to about 212 to 215 degrees F., due to the lowertemperature of the RAP. This was the temperature at the beginning of thewet mix step.

Separately, the AC, pine extract, biodiesel, and anti-stripping agentblend was prepared. The AC was maintained in a tank at 300 to 325degrees F. The pine extract, biodiesel, and anti-stripping agent startedat ambient temperature. They were blended into the AC. The resultingtemperature was about 210 degrees F.

In the wet mix step, the previously blended AC, pine extract, biodiesel,and anti-stripping agent were introduced and blended into the mix of RAPand virgin aggregate. After the wet mix step, the resulting temperaturewas about 190 degrees F.

The asphalt mix was stockpiled and/or bagged for use at ambienttemperatures. The stockpiles were about 42 tons. The stockpile wasreadily broken to get inside.

The asphalt mix was used for patching. It worked staying in the holesunder traffic load. It was workable at ambient temperatures for 4 monthsfrom the stockpile and 1 year from the bags.

The crusted material on the outside of the stockpile was integrated backinto the workable material with some manipulation and was salvageablerather than wasted.

Example 2

Formulation

The mix comprised four elements in percentages as follows: (1) coursevirgin aggregate-36.5%, (2) fine virgin aggregate-18%, (3) RAP-40%, and(4) a blend-5.5%—of asphalt cement, biodiesel, pine extract, andanti-stripping agent.

The composition of the blend was as follows: asphalt cement-67.5%,biodiesel-24%, pine extract-7%, and anti-stripping agent-1.5%.

The method of manufacturing was the same as for Example 1.

For the convenience of the reader, the above description has focused ona representative sample of all possible embodiments, a sample thatteaches the principles of the invention and conveys the best modecontemplated for carrying it out. The description has not attempted toexhaustively enumerate all possible variations. Other undescribedvariations or modifications may be possible. For example, where multiplealternative embodiments are described, in many cases it will be possibleto combine elements of different embodiments, or to combine elements ofthe embodiments described here with other modifications or variationsthat are not expressly described. Though the exact percentages aredefined and set for the user of the asphalt mix and method ofmanufacturing an asphalt mix, the stated percentages are examples andare approximate. Thus, the percentages may be defined as 1% of the pineextract and 28% of the biodiesel. The approximations may be plus orminus a certain percent such as 1% or 2%. The range for pine extract maybe 0.5% to 7.5% and the range for biodiesel may be 23.5% to 32.5%. Theamount of RAP may be 40% plus or minus about 5%. Many of thoseundescribed variations, modifications and variations are within theliteral scope of the following claims, and others are equivalent.

1. An asphalt mix comprising a pine extract, said asphalt mix having lowviscosity at ambient temperatures, and which is workable at ambienttemperatures.
 2. The asphalt mix of claim 1, wherein the asphalt mixcomprises asphalt cement, biodiesel, and pine extract.
 3. The asphaltmix of claim 2, wherein the asphalt mix further comprises ananti-stripping agent.
 4. The asphalt mix of claim 2, wherein the asphaltmix further comprises course aggregate.
 5. The asphalt mix of claim 2,wherein the asphalt mix further comprises fine aggregate.
 6. The asphaltmix of claim 2, wherein the asphalt mix further comprises recycledasphalt product.
 7. The asphalt mix of claim 2, wherein the compositionof the asphalt mix eliminates petroleum solvents beyond trace amounts.8. The asphalt mix of claim 1, wherein the asphalt mix is for patching.9. The asphalt mix of claim 1, wherein the asphalt mix comprises pineextract to improve workability.
 10. The asphalt mix of claim 1,comprising about 1% to 7% pine extract.
 11. The asphalt mix of claim 1,comprising about 1% pine extract.
 12. The asphalt mix of claim 1,comprising about 24% to 32% biodiesel.
 13. The asphalt mix of claim 1,comprising about 28% biodiesel.
 14. The asphalt mix of claim 1,comprising about 40% RAP.
 15. The asphalt mix of claim 1, wherein theasphalt mix is workable without machinery.
 16. The asphalt mix of claim1, wherein the asphalt mix is able to be stockpiled.
 17. The asphalt mixof claim 1, wherein the asphalt mix is bagged and stored and sold inbags.
 18. The asphalt mix of claim 1, wherein the asphalt mix is used atambient temperature.
 19. An asphalt mix comprising only solvents thatare biodegradable, said asphalt mix having low viscosity at ambienttemperatures, and which is workable at ambient temperatures.
 20. Theasphalt mix of claim 19, wherein the biodegradable solvents comprisepine extract.
 21. The asphalt mix of claim 19, wherein the biodegradablesolvents comprise pine extract and biodiesel.
 22. An asphalt mixconsisting of aggregate, RAP, AC, biodegradable solvents capable ofmaking the asphalt mix workable at ambient temperatures, andanti-stripping agent.
 23. The asphalt mix of claim 22, wherein thebiodegradable solvents comprise pine extract.
 24. The asphalt mix ofclaim 22, wherein the biodegradable solvents comprise pine extract andbiodiesel.
 25. A method of manufacturing an asphalt mix comprisingblending AC and pine extract.
 26. The method of manufacturing an asphaltmix of claim 25, comprising blending AC, pine extract and biodiesel. 27.A method of manufacturing an asphalt mix comprising extending a lengthof dry mixing RAP and aggregate.
 28. The method of manufacturing anasphalt mix of claim 27, wherein the length of the dry mixing is atleast about 35 seconds.
 29. The method of manufacturing an asphalt mixof claim 27, wherein the aggregate comprises coarse virgin aggregate andfine virgin aggregate.
 30. The method of manufacturing an asphalt mix ofclaim 27, wherein virgin aggregate is heated before the dry mix step tobe hot.
 31. The method of manufacturing an asphalt mix of claim 27,comprising introducing the RAP in an amount to make up about 40% of thefinal product.
 32. The method of manufacturing an asphalt mix of claim27, wherein the length of the dry mixing is extended until moisture issubstantially driven off.
 33. The method of manufacturing an asphalt mixof claim 27, wherein the length of the dry mixing is extended until ACfrom said RAP coats all aggregate.
 34. A method of manufacturing anasphalt mix comprising forming a coating of AC on all aggregate during astep of dry mixing RAP and aggregate.
 35. The method of manufacturing anasphalt mix of claim 34, wherein the length of the dry mixing is about35 seconds.
 36. The method of manufacturing an asphalt mix of claim 34,wherein the length of the dry mixing is extended until moisture issubstantially driven off.
 37. The method of manufacturing an asphalt mixof claim 34, wherein the aggregate comprises coarse virgin aggregate andfine virgin aggregate.
 38. The method of manufacturing an asphalt mix ofclaim 34, wherein the aggregate is heated before the dry mix step to behot.
 39. The method of manufacturing an asphalt mix of claim 34,comprising introducing the RAP in an amount to make up about 40% of thefinal product.
 40. A method of manufacturing an asphalt mix comprising:heating aggregate; introducing RAP to the aggregate; dry mixing the RAPand aggregate; forming a coating of AC on all aggregate during the stepof dry mixing; separately blending AC, biodegradable solvents, andanti-stripping agent to produce a blend; and wet mixing the blend intothe RAP and aggregate mix.
 41. The method of manufacturing an asphaltmix of claim 40, wherein the biodegradable solvents are capable ofmaking the asphalt mix workable at ambient temperatures.
 42. The methodof manufacturing an asphalt mix of claim 40, wherein the biodegradablesolvents comprise pine extract.
 43. The method of manufacturing anasphalt mix of claim 40, wherein the biodegradable solvents comprisepine extract and biodiesel.
 44. The method of manufacturing an asphaltmix of claim 40, wherein the length of the dry mixing is about 35seconds.
 45. The method of manufacturing an asphalt mix of claim 40,wherein the length of the dry mixing is extended until moisture issubstantially driven off.
 46. The method of manufacturing an asphalt mixof claim 40, wherein the aggregate comprises coarse virgin aggregate andfine virgin aggregate.
 47. The method of manufacturing an asphalt mix ofclaim 40, comprising introducing the RAP in an amount to make up about40% of the final product.
 48. The method of manufacturing an asphalt mixof claim 40, further comprising stockpiling the asphalt mix.
 49. Themethod of manufacturing an asphalt mix of claim 40, further comprisingbagging the asphalt mix.
 50. The method of manufacturing an asphalt mixof claim 48, further comprising manipulating encrusted material on theoutside of the stockpiled cold asphalt mix back into the stockpile.